Stock stop device for presses



Oct. 27, 1936. w MEUN STOCK STOP DEVICE FOR PRESSES Filed Sept. 28, 1934INVENTOR ATTO RNEYS Patented Oct. 27, 1936 UNITED STATES PATENT OFFICESTOCK STOP DEVICE FOR PRESSES William Melin, Detroit, Mich.

Application September 28, 1934, Serial No. 145,928

1 Claim.

The present invention pertains to a novel stop device for dies such asare used on punch presses for controlling the feeding action of stock asit is fed through the die, or in other words, means for positioning thestock for each successive working stroke of a press so that openings cutinto the stock will be uniformly spaced a predetermined distance apart.

The primary object of the present invention is to provide a latchmechanismor trigger device for engagingstock as it passes through apunch press, the mechanism being so arranged that it definitelypositions the took for each successive stroke of the press a d isthereupon retracted from engagement with the stock by the Working strokeof the punch so that the stock is free to move into position for thenext successive stroke. In performing this function it is another objectof the invention to provide a latch device including means forpreventing the latch from engaging the stock at the same place fromwhich it was retracted when the punch, which retracted .the latch by itsdown stroke, is travelling in its upward stroke.

Another object is to provide a latch mechanism as a unitary assembly sothat it may be easily assembled on a die in correct, operative position.

With the above and other ends in view the invention is more fullydisclosed with reference to the accompanying drawing, in which Figure 1is a vertical cross section of a die with my improved latch mechanismoperatively con-' nected thereto;

Fig. 2 is a plan of a die and stripper with the present mechanismassembled thereon;

Fig. 3 is a vertical cross section illustrating another stage ofoperation;

Fig. 4 is a top plan of the latch unit removed from the press; Fig. 5 isa transverse cross section thereof;

Fig. 6 is a bottom plan, and Fig. 7 is an end elevation. With referenceto the drawing the numeral I designates a die block having an opening 2conforming in shape to that of the part to be cut to those versed inthis particular art. It constitutes a simple conventional cutting orblanking die for cutting or punching flat pieces or blanks from a stripof stockand comprises a type of die with which the invention to bedescribed has 5 special utility. The mechanism which is associated with.the press'for moving the ram upwardly and downwardly in successivestrokes and the mechanism for feeding the stock through the die has notbeen illustratedhere because it is also 1 wellknown in the art and formsno part of the present invention.

The stripper plate 5 is provided with an aperture 9a in which the latchor trigger stop housing 9 is received, the housing being provided with15 laterally extending lugs I0 having slots I I through which fasteningscrews I2 are passed to enter the stripper plate. As shown in Figs. 1and 3 the aperture 911 is formed of greater length than the housing 9 sothat a small amount of lerigth- 20 wise adjustment movement of thehousing may take place when the fastening screws I2 are loosened, itbeing obvious that the slots ll permit such movement to take placebefore the screws I2 are tightened. When properly located, 25 thehousing is then dowelled at I211.

The housing 9 is provided with an open end It through which arocker armI3a extends. The latch element I3a is provided with an elongate slot I4intermediate its ends through which a 30 pin I5 extends. The pin I5 isfirmly mounted in the housing 9 and serves as a fulcrum for the latchelement I3 and it is obvious that the elongation of the slot permits alimited amount of lengthwise movement of the latch element as well 5 aspivotal movement thereof, the length of the slotdetermining the amountof lengthwise movement. Formed on the latch element I3a is a shoulder I6which is engaged by a spring II, the latter being secured as at I8 tothe housing 9 4g and functioning to resiliently urge the latch member toa position where one end of the slot It engages the pin I5 andcooperating with the spring 23 in engagement with the groove 24 forresiliently urging outward pivotal movement of 45 the latch element. Inthe absence of any external pressure the spring I'I moves the latchelement toa position where its forward end I9 is depressed to a positionoutwardly of the housing 5.

On the other end of the latch element is pivotally mounted a stem 20which extends upwardly through an opening 2If in the housing 9 to beengaged by an adjustable tappet 22 carried by the movable section 3 ofthe die.

In operation, the stock 8 is fed into the press and as the die section 3descends the punch 4; by a shearing action, cuts through the stock as itenters the die opening ,2, leaving an opening in the stock. After thedie section 3 ascends, the

forward end of the latch element l3a is projected 1 by the spring i1intothe opening thus formed in the stock 8 and as the stock feedingmovement is continued the side wall of the opening strikes against theend of the latch element. Further forward end I8 is retracted from theopening inthe stock and the spring l'l functions to move the latchelement toward the punch 4 so that the end i9 is moved out of alignmentwith the said opening. As the die section 3 again ascends the end l9rides along the top surface of the stock as the stock is again advancedthrough the press,

and the same operation is repeated in connection with each successiveopening cut into the stock by successive operations of the die.

By providing a housing adjustable temporarily by the screws l2 and thenpermanently or fixedly by the dowels l2a it becomes possible toconstruct a latch mechanism as a unitary devicewhich may be sold inassembly as distinguished from present practice of assembling variousparts on a die at the time of setting up a machine.

Further, the use of the lugs W as provided herein renders it feasible toadjust the height of the housing '9 by means of shims 2!.

Although a specific embodiment of the present invention has been shownand described in combination with a specific 'type of press it will beunderstood that various changes may be made within the scope of theappended claim without departing from the spirit of the invention, andsuch changes arecontemplated.

What I claim is:- In combination with the stripper plate of a die havingan elongated opening therethrough and holes adjacent said opening, alatch mechanism comprising a housing having smaller longitudinaldimension than said opening for insertion-thereinto and for adjustmentwith respect thereto, lugs extending laterally from said housing andhaving elongated openings therethrough for placement over the holes insaid plate whereby temporary holding means may be inserted therethrough,and dowel means fixedly positioning saidhousing in said opening afteraccurate adjustment thereof, said housing having a pin fixedly mountedtherein, a rocker arm mounted on said pin in loose longitudinalengagement I therewith for endwise sliding movement, a trip pin mountedon one end of said rocker arm and extending outwardly through the top ofsaid plate. 1

WILLIAM mm.

